Coal Preparation

Advanced Control and Optimisation of DMC Operation

Coal Preparation » Process Control

Published: June 18Project Number: C22033

Get ReportAuthor: Shenggen Hu | CSIRO

The objective of this project was to develop, implement and demonstrate a system that determines the optimal DMC cut‐point at which a target product ash and/or a given incremental ash can be achieved. The operation of dense medium cyclone (DMC) at the optimal cut‐point would reduce the amount of product with out‐of-specification ash and maximise the yield of a plant with multiple parallel beneficiation units.

The system combines online measurements of medium densities and DMC product yield with predictive models for on‐line determinations of the partition curve, the feed coal washability and the product ash and/or incremental ash. The partition curve and the plant feed washability are determined using methods developed in two previous projects (C13058, C20049). The system will help the control system to get the most out of limited measurements by determining the current cut‐point and predicting the optimal cut‐point.

Methods for predicting instantaneous ash curve for known and unknown coal sources were developed. A versatile empirical equation was developed for fitting any type of instantaneous ash curve. It was found that the averaged instantaneous ash curve from bore‐hole logs with weighted coefficients related to the seam thickness in each hole for a given seam or a seam mixture with a constant blending ratio has a sufficient accuracy for predictions of the product ash and the incremental ash, and this is valid even for coal feeds with intra‐seam or out‐of‐seam dilutions. It was also found that the washability curve from the bore‐hole logs is still useful for predicting the product ash in cases where the coal feed has a significant intra‐seam dilution from shale bands as long as the cut‐point is lower than 1.6RD.

The effects of errors in instantaneous ash curve on the predictions of the product ash and incremental ash have been thoroughly investigated using simulated cases. A ±1% error (absolute error) in the ash value at the density of 1.27RD on the instantaneous ash curve can cause about ±0.8% error (absolute error) in the predicted product ash value. Errors at the density of 1.65RD on the instantaneous ash curve have an insignificant impact on the prediction.

Results from plant‐based experiments indicated that the predicted product ash values were close to those from sampling and laboratory analysis for coal feeds from a mixture of seams or a single seam. The plant-based experimental results demonstrated that the method was effective in the simultaneous determination of the plant feed washability and the instantaneous ash curve through the perturbation of the correct medium density and accompanied by product sampling and rapid ash analysis. The method for determining the optimal cut‐point for a given product ash or incremental ash was successfully demonstrated in plant experimental cases.

The methods developed in this project are useful not only for online applications, but also for optimisation through sampling. Data from Marcy density gauge and rapid ash analysis are collected at three correct medium densities: i.e. current set‐point, +0.05RD higher and ‐0.05RD lower, and then used to estimate the instantaneous ash and the washability curves of unknown coal feed sources. Finally the cut‐point for the targeted product ash and/or incremental ash would be found.

The system and methods have considerable potential to add value to the Australian coal preparation industry by maximising the plant yield. Applications of the system and methods at mine sites require further improvements and integration of the system with existing plant systems. Development of an Excel Spreadsheet based program is also desirable for the optimisation through sampling.


Health and safety, productivity and environment initiatives.

Recently Completed Projects

C34019Longwall Bretby Cable Handling Monitoring With Fibre Optics

This project examined the potential of using fibre optic sensing tec...

C28028The Inclusion Of High Interest Native Plants In Mine Site Restoration Programs: Propagation, Translocation And Field Re-Introduction

This report synthesises over 10 years of ex situ and in si...

C27049Mine Machine Radar Sensor Integration

The aim of this project was to develop an integrated radar sensor an...


Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C34029Validation Of Laser Induced Breakdown Spectroscopy (LIBS) As A Rapidly Deployable Field Technology To Estimate Coal Quality

Rapid evaluation of a coal resource by in-situ characterisation dow...

C34028Guidelines For Assessment Of Geotechnically Safe And Stable Post-Mining Landforms

The purpose of this project was to develop a guidelines document as ...

C34016Elements In Coal – A Start-To-End Analysis

This project explores the fate and concentration potential of critical e...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C26016Determining The Benefits Of Online Thickener Underflow Rheology Measurements

The aim of this project is to determine how useful the rheology meas...

C33056Modelling And Control Of Classifying Cyclones

Hydrocyclones are one of the key technologies for the classification...

C28056Surface Alloying Of Centrifuge Baskets And Sieve Bends Screen Surfaces To Increase The Service Lifetime

The main objective of this project was to improve the wear resistanc...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C33066Washability And Distribution Of Sulfur And Trace Elements For Different Size And Density Fractions Of Raw Coals

Based on the hypothesis that the levels of sulfur and other toxic tr...

C34060In-Situ Investigation Of Coke Structure Formation Under Stamp Charged Coking Conditions

Stamp charged cokemaking has emerged as an effective technique to im...

C34062Improving The Classification Of Microstructure Distribution In Coke CT Images Using Deep Learning And Lineal Path Calculations

This project builds on a number of earlier projects that have helped...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C28076Selective Absorption Of Methane By Ionic Liquids (SAMIL)

This third and final stage of this project was the culmination of a ...

C29069Low-Cost Catalyst Materials For Effective VAM Catalytic Oxidation

Application of ventilation air methane (VAM) thermal oxidiser requir...

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement

This multi‐phase project is concerned with the mitigation of m...

Mine Site Greenhouse Gas Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

Mining And The Community


National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook